在 2022/10/14 11:43, Andrii Nakryiko 写道:
On Thu, Oct 13, 2022 at 7:24 PM wangyufen <wangyufen@xxxxxxxxxx> wrote:在 2022/10/14 3:47, Andrii Nakryiko 写道:On Mon, Oct 10, 2022 at 3:40 AM Wang Yufen <wangyufen@xxxxxxxxxx> wrote:Add autoattach optional to support one-step load-attach-pin_link. For example, $ bpftool prog loadall test.o /sys/fs/bpf/test autoattach $ bpftool link 26: tracing name test1 tag f0da7d0058c00236 gpl loaded_at 2022-09-09T21:39:49+0800 uid 0 xlated 88B jited 55B memlock 4096B map_ids 3 btf_id 55 28: kprobe name test3 tag 002ef1bef0723833 gpl loaded_at 2022-09-09T21:39:49+0800 uid 0 xlated 88B jited 56B memlock 4096B map_ids 3 btf_id 55 57: tracepoint name oncpu tag 7aa55dfbdcb78941 gpl loaded_at 2022-09-09T21:41:32+0800 uid 0 xlated 456B jited 265B memlock 4096B map_ids 17,13,14,15 btf_id 82 $ bpftool link 1: tracing prog 26 prog_type tracing attach_type trace_fentry 3: perf_event prog 28 10: perf_event prog 57 The autoattach optional can support tracepoints, k(ret)probes, u(ret)probes. Signed-off-by: Wei Yongjun <weiyongjun1@xxxxxxxxxx> Signed-off-by: Wang Yufen <wangyufen@xxxxxxxxxx> --- tools/bpf/bpftool/prog.c | 78 ++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 76 insertions(+), 2 deletions(-) diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c index c81362a..8f3afce 100644 --- a/tools/bpf/bpftool/prog.c +++ b/tools/bpf/bpftool/prog.c @@ -1453,6 +1453,69 @@ static int do_run(int argc, char **argv) return ret; } +static int +auto_attach_program(struct bpf_program *prog, const char *path) +{ + struct bpf_link *link; + int err; + + link = bpf_program__attach(prog); + if (!link) { + p_info("Program %s does not support autoattach, falling back to pinning", + bpf_program__name(prog)); + return bpf_obj_pin(bpf_program__fd(prog), path); + } + err = bpf_link__pin(link, path); + if (err) { + bpf_link__destroy(link); + return err; + }leaking link here, destroy it unconditionally. If pinning succeeded, you don't need to hold link's FD open anymore.I got it, will change. Thanks！+ return 0; +} + +static int pathname_concat(const char *path, const char *name, char *buf)why you didn't do the same as in libbpf? Pass buffer size explicitly instead of assuming PATH_MAXThe pathname_concat function is invoked only in one place and is not a general function here. So, not modified. Or, can I change the "pathname_concat" of libbpf to "LIBBPF_API int libbpf_pathname_concat" and use the libbpf_pathname_concat directly?no need to reuse libbpf's helper, but I do think it's cleaner to specify not just buffer pointer, but also it's size, just like you do with any other string buffer API (like snprintf)
OK, will change in v9 too. Thanks！
+{ + int len; + + len = snprintf(buf, PATH_MAX, "%s/%s", path, name); + if (len < 0) + return -EINVAL; + if (len >= PATH_MAX) + return -ENAMETOOLONG; + + return 0; +} + +static int +auto_attach_programs(struct bpf_object *obj, const char *path) +{ + struct bpf_program *prog; + char buf[PATH_MAX]; + int err; + + bpf_object__for_each_program(prog, obj) { + err = pathname_concat(path, bpf_program__name(prog), buf); + if (err) + goto err_unpin_programs; + + err = auto_attach_program(prog, buf); + if (err) + goto err_unpin_programs; + } + + return 0; + +err_unpin_programs: + while ((prog = bpf_object__prev_program(obj, prog))) { + if (pathname_concat(path, bpf_program__name(prog), buf)) + continue; + + bpf_program__unpin(prog, buf); + } + + return err; +} + static int load_with_options(int argc, char **argv, bool first_prog_only) { enum bpf_prog_type common_prog_type = BPF_PROG_TYPE_UNSPEC; @@ -1464,6 +1527,7 @@ static int load_with_options(int argc, char **argv, bool first_prog_only) struct bpf_program *prog = NULL, *pos; unsigned int old_map_fds = 0; const char *pinmaps = NULL; + bool auto_attach = false; struct bpf_object *obj; struct bpf_map *map; const char *pinfile; @@ -1583,6 +1647,9 @@ static int load_with_options(int argc, char **argv, bool first_prog_only) goto err_free_reuse_maps; pinmaps = GET_ARG(); + } else if (is_prefix(*argv, "autoattach")) { + auto_attach = true; + NEXT_ARG(); } else { p_err("expected no more arguments, 'type', 'map' or 'dev', got: '%s'?", *argv); @@ -1692,14 +1759,20 @@ static int load_with_options(int argc, char **argv, bool first_prog_only) goto err_close_obj; } - err = bpf_obj_pin(bpf_program__fd(prog), pinfile); + if (auto_attach) + err = auto_attach_program(prog, pinfile); + else + err = bpf_obj_pin(bpf_program__fd(prog), pinfile); if (err) { p_err("failed to pin program %s", bpf_program__section_name(prog)); goto err_close_obj; } } else { - err = bpf_object__pin_programs(obj, pinfile); + if (auto_attach) + err = auto_attach_programs(obj, pinfile); + else + err = bpf_object__pin_programs(obj, pinfile); if (err) { p_err("failed to pin all programs"); goto err_close_obj; @@ -2338,6 +2411,7 @@ static int do_help(int argc, char **argv) " [type TYPE] [dev NAME] \\\n" " [map { idx IDX | name NAME } MAP]\\\n" " [pinmaps MAP_DIR]\n" + " [autoattach]\n" " %1$s %2$s attach PROG ATTACH_TYPE [MAP]\n" " %1$s %2$s detach PROG ATTACH_TYPE [MAP]\n" " %1$s %2$s run PROG \\\n" -- 1.8.3.1
